Drug compositions that increase duration of pain control and decrease risk of tolerance and side effects are generally desirable. Due to side effects associated with narcotics, including for example sedation, respiratory depression, tolerance, and addiction, it is desirable to manage pain without narcotic drugs. However, non-narcotic methods of pain control are sometimes inadequate in intensity, duration or both.
For example, painkillers such as non-steroidal anti-inflammatory drugs (NSAIDs) are often not strong enough to control pain where a patient undergoes surgery or other invasive procedure or has suffered significant trauma. Although local anesthetics (e.g., amides) administered as nerve blocks can be useful for pain control, such blocks using amides are often inadequate in duration. Moreover, esters have not been an option of choice for use as a local anesthetic for nerve blocks, likely because the duration of pain control associated with ester drugs was known to be excessive, and to impair mobility for excessive durations, when esters were used as spinal anesthetics. Additionally, metabolism of esters by cholinesterases has potential for toxic effects by metabolites, such as 4-aminobenzoic acid (PABA).
As such, non-narcotic pharmaceutical compositions and corresponding methods of treatment that provide an adequate intensity and duration of pain management are desirable. The pharmaceutical compositions disclosed herein, which contain an ester anesthetic composition and a cholinesterase inhibitor compound, and methods of treatment using such pharmaceutical compositions unexpectedly provide advantages in management of pain. Optionally in a preferred embodiment, these pharmaceutical compositions may also contain an amide anesthetic.
Local anesthetic drug combinations and methods of treatment that can provide greater duration, reliability, reproducibility and a reduction in adverse events as compared with narcotics use (e.g., breathing difficulty, addiction) are highly desirable. The present pharmaceutical compositions and methods of treatment unexpectedly provide such advantages.
The present compositions and methods of treatment unexpectedly provide an increased duration of pain control by nerve block as compared with prior pharmaceutical compositions and methods for nerve block. As such, the present compositions and methods unexpectedly result in a decreased need for narcotic drug administration and provide decreased sedation and increased respiratory output as compared with prior pain control compositions and methods which employ narcotics. The present pharmaceutical compositions and methods of use provide unexpectedly high levels of patient satisfaction and decrease interventions required by health care personnel for pain management, including a beneficial effect on pain management particularly in the first 24 hour post-operative period.